Scraper dump control



Nov. 20, 1945. R. B. LAIRD SCRAPER DUMP CONTROL Filed Aug. 12, 1944 RoyaLBLa z'rd Patented Nov. 20, 1945 UNITED STATES PATENT OFFICE 2,389,199 scRAPER DUMP CONTROL Royal B. Laird, Mei-cell, Calif. Application August 12, 1944, Serial No. 549,167

'1 Claim. (01. amiss) This invention relates general to an earth worlring scraper and in particular the invention is directed to, and it is an object to provide, a

novel device tocontrol the tiltin and resultant dumping of the scraper bowl.

An additional object of the invention is to embody in a scraper which includes a tilta'ble bowl of generally the Fresno type, a tilt control device of unique construction and operation; such device extending from the bowl to the draft frame and-being normally locked, manually releasable, and automatically resetting.

A further object of the present invention is to provide a tilt control device, as in the preceding paragraph, which comprises between a part of the draft frame and a part on the bowl which moves forwardly "upon tilting of said bowl, a compression rod connected to one of said parts, a guide connected to the other part and supporting the rod for relative sliding movement, and a normally engaged but releasable lock between the guide and rod, said lock being arranged to engage with the rod in locking relation to the latter at different points along the length thereof.

A further object of the invention is to produce a simple and inexpensive device and yet one which will be exceedingly effective for the purpose for which it is designed.

Figure 3 is a similar view but showing the trip I lever as unlocked from the rod.

Figure 4 is a fragmentary rear end view of the A-frame portion of the lift frame, detached.

Referring now more particularly to the characters of reference on the drawing, my improved tilt control device is here shown as embodied in connection with a drag type of scraper of generally the Fresno type, and which includes a bowl I havin a back plate 2 fitted on its lower edge with a cutting blade 3. At the ends the bowl I includes forwardly projecting rigid side wings 4.

The bowl I is connected in draft relation to the tractor, which is indicated'generally at 5, by means of a combined draft and power actuated lift frame, indicated generally at '6, such as is commonly used inconnection with wheeled tractors or the like.

Tneuraft frame 6 includes an upstanding A-' frameportion 'I, as shown in detail in Figure '4, which faces to the rear and includes downwardly diverging legs 8. At their lower ends the legs 8 are pivotally connected, as at 9, to the forward ends of rigid draft ar'ms I0, which project rearwardly along the outside of the side wings '4. The rear ends of the draft 'arms ID are pivotally connected to the side wings 4, as at II.

Ina scraper bowl of the type described the side wings 4 ride on the ground and the frictional drag of said side wings tends to rotate the bowl a "direction to raise the blade 3, and to cause the upper edge of the back plate 2 to move upwardly and forwardly. This rotative movement causes the bowl I to dump; the extent of the dump or spreading operation being regulated by the amount of rotation of the bowl. Such rotation is controlled by the device which is the subject of the present invention and which comprises the following arrangement:

A compression rod I2 is pivotally connected at its rear end to the upper edge portion of the back plate 2 of the bowl I and centrally of the ends of the latter by means of a clevis unit l3. The rod I2 extends forwardly toward the A- frame portion 1, and passes axially through a longitudinally disposed tubular body I 4; such rod being supported at opposite ends of the body I4 by annular guide shoulders I5. The tubular body I4 is suspended from the A-frame portion I in vertically swingable relation by means of an upstanding yoke IS on the body pivoted to an ear H which depends from the A-frame portion I centrally between the upper ends of the legs 8.

The forward end portion of the rod I2 is threaded as at I8, and this threaded portion carries an adjustable stop nut I9 which limits the extent to which the rod I2 may retract from the body I4. It will be evident that control of the forward or advancing sliding movement of the rod I2 relative to the body I4 from the normal position of these parts, as shown in full lines in Fig. 1, will regulate with a bore 22 through which the rod l 2 extends; such bore being somewhat oversize relative to the diameter of rod l2; the axis of said bore preferably being parallel to the rod when the lever is disposed with a forward slope. The portion of the body l4 at the forward end of the opening 20 provides a stop, indicated at 23. A heavy-duty compression spring 24 surrounds the rod l2 in the body I 4 between the rear end of the latter and the trip lever 2 I This spring normally acts to urge theuppe'r end portion of trip lever 2| forwardly about stop 23 as a fulcrum. When this occurs, the rod 12 binds in the bore 22, and the trip lever is then, in effect, fixed to said rod and any tendency of the rod to advance is prevented by reason of the trip lever engaging stop 23.

When the operator of the tractor desires to' permit the bowl I to tilt and dump, he pulls on a cord 25 which leads from adjacent the opera-.

tors seat to the lower end of the trip lever 21. This causes such lever to be swung rearwardly at its upper end portion, releasing the rod 12, as shown'in Fig. 3, and permitting the rod l2 to slide forwardly, which in turn allows the bowl to rotate in a dumping direction. The extent of tilting can be effectively controlled, and to any desired extent, betweenthe limits of movement of the bowl, as the operator need merely release the J32! substantially fulfills the objects of the invention as set forth herein While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations, from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claim.

Having thus described my invetnion, what I :claim as new and useful and desire to secure by Letters Patent is:

A means to control the revoluble action of a tractor drawn revolving scraper; such means comprising a, frame supported by the tractor, a tubular body pivotally supported at one end to said frame, said body being closed at both ends and having a slot formed in its side, a rod slidable through the ends of the body, stops means on one end of the rod adapted to engage the adjacent end of the body to limit the movement of the rod in' one direction, means on the other end of the rod adapted for attachment to the scraper, a lever depending through the slot, the lever being provided with a bore through which the rod projects, the diameter of the bore being slightly greater than the diameter of the rod and the wall of the bore being normally out of parallel with the rod, whereby when the lever is suspended in a substantially vertical position from the rod the lever will grip the rod about the bore, yieldable means normally urging the lever into rod gripping position, and means to cant the lever at an angle to the vertical and bring the wall of the bore into substantial parallelism with the rod whereby to allow the rod to slide freely through the bore and tubular body.

ROYAL B. LAIRD. 

